/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * mm/mm_gran/mm_granfree.c
 *
 *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <assert.h>

#include <tinyara/mm/gran.h>

#include "mm_gran/mm_gran.h"

#ifdef CONFIG_GRAN

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Name: gran_common_free
 *
 * Description:
 *   Return memory to the granule heap.
 *
 * Input Parameters:
 *   handle - The handle previously returned by gran_initialize
 *   memory - A pointer to memory previoiusly allocated by gran_alloc.
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

static inline void gran_common_free(FAR struct gran_s *priv, FAR void *memory, size_t size)
{
	unsigned int granno;
	unsigned int gatidx;
	unsigned int gatbit;
	unsigned int granmask;
	unsigned int ngranules;
	unsigned int avail;
	uint32_t     gatmask;

	DEBUGASSERT(priv && memory && size <= 32 * (1 << priv->log2gran));

	/* Get exclusive access to the GAT */

	gran_enter_critical(priv);

	/* Determine the granule number of the first granule in the allocation */

	granno = ((uintptr_t)memory - priv->heapstart) >> priv->log2gran;

	/* Determine the GAT table index and bit number associated with the
	 * allocation.
	 */

	gatidx = granno >> 5;
	gatbit = granno & 31;

	/* Determine the number of granules in the allocation */

	granmask = (1 << priv->log2gran) - 1;
	ngranules = (size + granmask) >> priv->log2gran;

	/* Clear bits in the GAT entry or entries */

	avail = 32 - gatbit;
	if (ngranules > avail) {
		/* Clear bits in the first GAT entry */

		gatmask = (0xffffffff << gatbit);
		DEBUGASSERT((priv->gat[gatidx] & gatmask) == gatmask);

		priv->gat[gatidx] &= ~gatmask;
		ngranules -= avail;

		/* Clear bits in the second GAT entry */

		gatmask = 0xffffffff >> (32 - ngranules);
		DEBUGASSERT((priv->gat[gatidx + 1] & gatmask) == gatmask);

		priv->gat[gatidx + 1] &= ~gatmask;
	}

	/* Handle the case where where all of the granules came from one entry */

	else {
		/* Clear bits in a single GAT entry */

		gatmask = 0xffffffff >> (32 - ngranules);
		gatmask <<= gatbit;
		DEBUGASSERT((priv->gat[gatidx] & gatmask) == gatmask);

		priv->gat[gatidx] &= ~gatmask;
	}

	gran_leave_critical(priv);
}

/****************************************************************************
 * Global Functions
 ****************************************************************************/

/****************************************************************************
 * Name: gran_free
 *
 * Description:
 *   Return memory to the granule heap.
 *
 * Input Parameters:
 *   handle - The handle previously returned by gran_initialize
 *   memory - A pointer to memory previoiusly allocated by gran_alloc.
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

#ifdef CONFIG_GRAN_SINGLE
void gran_free(FAR void *memory, size_t size)
{
	return gran_common_free(g_graninfo, memory, size);
}
#else
void gran_free(GRAN_HANDLE handle, FAR void *memory, size_t size)
{
	return gran_common_free((FAR struct gran_s *)handle, memory, size);
}
#endif

#endif							/* CONFIG_GRAN */
